The present invention relates to data center infrastructure, and more particularly, this invention relates to switch clusters having Layer-3 distributed router functionality.
A common practice for software-defined network (SDN) controllers is to use the OpenFlow protocol to create a logical OpenFlow domain or a switch cluster comprising a plurality of switches therein. However, any other protocol may be used to create these switch clusters. The switch cluster does not exist in a vacuum and communication with entities outside of the switch cluster is needed in order to function in a real application. This communication typically takes place with non-SDN Layer-2/Layer-3 (L2/L3) devices and networks.
L2 communications with a non-SDN device is typically handled in any commercially available SDN controller, such as an OpenFlow controller utilizing Floodlight. However, conventional SDN controllers are not capable of handling L3 communications.
One prior attempt to provide L3 communications to a switch cluster is virtual router support in NEC's Programmable Flow Controller; however, it relies on a ternary content-addressable memory (TCAM)-based OpenFlow Table alone, which in most switches has a significantly lower number of flow table entries and hence does not scale effectively to be used in switch clusters.
Accordingly, it would be beneficial to provide a mechanism to provide L3 support for a SDN-based switch cluster in a scalable fashion. Existing conventional methods to accomplish L3 communications rely on OpenFlow 1.0 style TCAM tables, also known as access control list (ACL) tables, alone which are expensive to implement and typically have a much lower number of total entries.